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## Creator

[Frederico G. Alabarse](https://orcid.org/0000-0002-7375-3666), Benoît Baptiste, Yoann Guarnelli, [Yohei Onodera](https://orcid.org/0000-0002-3080-6991), [Shinji Kohara](https://orcid.org/0000-0001-9596-2680), [Julien Haines](https://orcid.org/0000-0002-7030-3213)

## Rights

This document is the Accepted Manuscript version of a Published Work that appeared in final form in Journal of Physical Chemistry Letters, copyright © 2024 American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see　https://doi.org/10.1021/acs.jpclett.4c00853. [In Copyright](http://rightsstatements.org/vocab/InC/1.0/)

## Other metadata

[Direct Single Crystal to Amorphous Transformation and Memory Effect in AlPO<sub>4</sub>-17](https://mdr.nims.go.jp/datasets/53fdab94-a206-4ba5-94da-f0bcb21e372e)

## Fulltext

Microsoft Word - jz-2024-00853n_R1.docxDDiirreecctt  SSiinnggllee  CCrryyssttaall  ttoo  AAmmoorrpphhoouuss  TTrraannssffoorrmmaattiioonn  aanndd  MMeemmoorryy  EEff--ffeecctt  iinn  AAllPPOO44--1177..  Frederico G. Alabarsea, Benoît Baptisteb, Yoann Guarnellib,  Yohei Onoderac, Shinji Koharac, and Ju-lien Hainesd,*  aElettra Sincrotrone Trieste, Trieste 34149, Italy  bInstitut de Minéralogie, de Physique des Matériaux et de Cosmochimie, (IMPMC) UMR 7590 CNRS – Sorbonne Université – IRD – MNHN, 4 place Jussieu, 75252 Paris Cedex 5, France  cCenter for Basic Research on Materials, National Institute for Materials Science,  1-2-1 Sengen, Tsukuba, Ibaraki 305-0047, Japan.  dInstitut Charles Gerhardt Montpellier, Université de Montpellier, CNRS, ENSCM, 34293 Montpellier, France  *E-mail: Julien.haines@umontpellier.fr  ABSTRACT: Pressure induced amorphization provides a distinct route to prepare novel amorphous materials. Single crystals of the porous aluminophosphate AlPO4-17 directly transform to an amorphous state beginning at 0.6 GPa, without fragmen-tation into polycrystalline material. Apart from a reduction in dimensions, the amorphous material retains the form of the initial single crystal. Remnant crystalline domains in the amorphous material also preserve the initial orientation of the single crystal. X-ray diffraction indicates the compression of the structure around the empty pores in the xy plane and such an amor-phization mechanism is consistent with a direct structural relationship between the single crystal and amorphous forms. The collapse of the initial pore volume is almost complete at 2.5 GPa. A memory effect is observed in the amorphous form, which strongly expands on decompression. The present process opens the way for the synthesis of topologically-ordered amor-phous materials approaching “perfect glasses” with improved mechanical properties.    The use of high pressure is a powerful tool to obtain new amorphous materials with distinct structural and physical properties with respect to standard glasses1-3. In particular, pressure was found to produce a novel  amorphous  form  of  ice4.  There was  also  considerable  interest placed  in  the  amorphization  of  quartz  SiO25-7  and  various minerals1. Pressure-induced  elastic  softening  has  been  identified  in  materials with the unusual property of negative thermal expansion8 followed in a large number of cases by amorphization such as in the case of zirco-nium  tungstate  ZrW2O89-10.  Both negative  thermal  expansion11-13  and pressure-induced amorphization14-21 occur in a large number of porous materials,  such  as  zeolites.  Additionally,  in  the  case  of  zeolites,  slow compression opens the way for the synthesis of “perfect” or ordered glasses16.  Such  “perfect  glasses”  exhibit  a  degree  of  structural  order, low entropy and low fragility. The dense amorphous form obtained by the room temperature compression of the pure silica zeolite, silicalite-1, with the Mobil-five structure, was found to retain the framework to-pology of the starting zeolite, but is amorphous due to strong geomet-rical distortions17. This topologically ordered amorphous form exhibits permanent  densification  after  compression  at  room  temperature  in contrast to silica glass22. The  aluminophosphate,  AlPO4-17,  with  the  porous  hexagonal  eri-onite (ERI) structure (space group P63/m), is the zeolite-type material with the highest coefficient of negative thermal expansion23 and exhib-its  an  elastic  instability  and  pressure-induced  amorphization  begin-ning near 1 GPa20. In the present study, single crystals of this material are  found to transform directly to the amorphous state retaining the form and orientation of the initial crystal. Single-crystal x-ray diffrac-tion indicates a collapse of the pore network leading to amorphization. Single  crystals  (110-160  µm  maximum  dimensions)  of  AlPO4-17 (Figure 1a) were studied under hydrostatic pressure in DAPHNE 7474 oil24 by single-crystal x-ray diffraction (XRD) in a diamond anvil cell at the Xpress beamline at the Elettra Sincrotrone Trieste. The ERI struc-ture of AlPO4-1723 is built up of columns of alternating cancrinite (can) cages and double 6-membered ring (D6MR) secondary building units along the c direction with larger erionite (eri) cages between the col-umns (Figure 2a,b).   Figure  1.  Optical  images  of  investigated  single  crystal  and amorphous AlPO4-17 in the diamond anvil cell (a). X-ray rota-tion photographs  (l=0.4956 Å) of AlPO4-17 at  selected pres-sures (b).  Figure  2.  Projection  of  the  polyhedral  representation  of  the crystal structure of AlPO4-17 along x (a) and z (b). Cell param-eters of  single-crystal AlPO4-17 as a  function of pressure  (c). Relative unit cell volume and relative pore volume of AlPO4-17 as a function of pressure (d). Data for the dense crystalline form of AlPO4, berlinite,  from the  literature are given for compari-son26. The XRD data were of high quality with very good agreement factors for the structure refinements up to 0.6 GPa (Tables S1-S55). Up to this pressure, compression proceeded in a conventional manner (Figure 2c, S1) with similar compressibilities along the a (0.0081(2) GPa-1) and c (0.0111(5) GPa-1) directions and no direct evidence of elastic softening. The pressure dependence of the unit cell volume (Figure 2d) can easily be  fitted  to  a  standard  second-order Birch-Murnaghan25  equation  of state with a bulk modulus of 36(1) GPa and an implied first pressure derivative of 4 (Figure S2a). The Al-O-P angles most affected over this pressure range are the angles in the xy plane in the 4 membered rings (4MR) in the D6MR (Figure S3). The other angles remain quite stable. The main change is to the porous volume corresponding to the empty pores and cages (Figure 2d), which with a bulk modulus of 14(4) GPa (Figure 2b) decreases 2.6 times more rapidly than the unit cell volume and considering that the porous volume accounts for 38% of the unit cell volume,  the compression mechanism correspond almost entirely to the collapse of the structure around the empty pores. At 0.55 GPa, for example, the reduction in pore volume of 32 Å3 corresponds exactly to the total reduction in unit cell volume. Beginning  above  0.7  GPa,  elastic  softening  begins  in  the  xy  plane (Figure 2c) with decreases in the in-plane Al-O-P angles in the large eri cages (Figure S3). Concomitantly, a close to 30% decrease in intensity (Figure 3a) and broadening of the reflections of the single crystal are observed  without  the  formation  of  polycrystalline  material.  At  the same time, values of the agreement R-factors for the single crystal dou-ble (see supporting information). Another major decrease in intensity by more than a factor of two follows above 1.1 GPa. At this pressure, the diffuse signal of the amorphous form (Figure 1b) is clearly visible in x-ray rotation images, and based on its intensity, the majority of the material is already amorphous at this pressure. Additionally, in the re-maining crystalline phase above 0.9 GPa a large number of superlattice hkl reflections  (Figure S4) with half integer indices in h and k (i.e. 1/2 0 8, 3/2 0 2, 3/2 5/2 4, etc.) with a maximum relative intensity of 4% appear indicating cell doubling along a and b as has also been found in oxygen filled AlPO4-17 at much higher pressure27. No clear distortion from a hexagonal unit cell metric is observed and any eventual lower-ing in symmetry could not be reliably determined due to the reduction in data quality at this pressure. Due to this reduced data quality, struc-ture refinements were performed using the undoubled hexagonal sub-cell over the 0.9-1.2 GPa pressure interval, above which only the unit cell parameters could be refined. Cell doubling enables increased flexi-bility and subsequent rapid collapse of the decreasing amount of rem-nant crystalline material, which is progressively becoming amorphous with each further increase in pressure. Even though there is a decrease in crystal quality, the diffraction data continue to correspond to a single crystal albeit with a degree of strain corresponding the stress gradients experienced by the single crystal domains embedded in the amorphous material (Figure 1b). In addition, the orientation of the remnant crystal domains and the form of the macroscopic amorphous material are the same as that of the initial single crystal. These results are evidence for a direct relationship between the structure of the single crystal AlPO4-17 and the collapsed network of the amorphous form around the empty pores, similar to the process in which the silicalite-1 structure collapses upon amorphization while retaining the structural topology of the crys-talline phase17. The first stages of this collapse in AlPO4-17 around the empty pores are clearly demonstrated by refined structures of the crys-tal up to 1.2 GPa (Figure 2d and Tables S2-S55).   The  diffuse  halo  corresponding  to  the  first  sharp  diffraction  peak (FSDP) increases in intensity and shifts to higher Q values with increas-ing  pressure  (Figure  3b).  The  increase  in  FSDP  is  an  indication  of  a modification  of  the  intermediate  range  structure  of  the  amorphous form and for higher pressures, the values are similar to those of silica glass28. A large decrease in the FSDP occurs on pressure release with a value similar to that of recovered amorphous AlPO4-1720 (Figure S5). This decrease indicates that the changes in intermediate range struc-ture are reversible. The relative volume and density of the amorphous form at ambient pressure, estimated by the reduction in single crystal dimensions upon transformation to the amorphous form (Figure 1a), are 0.92 and 1.7 g/cm3, respectively. An independent determination of the density based on the initial slope of the reduced pair distribution function G(r) from a previously-obtained, recovered, amorphous pow-der sample (Figures S6 and S7) yields a density of close to 1.6 g/cm3. This  is  essentially  the  same  as  that  of  the  initial  crystal  of  AlPO4-17 (1.607 g/cm3). This low density is consistent with recovery of a signif-icant degree of pore volume providing evidence for the retention of the initial structural topology in the amorphous form. The changes in in-termediate range structure corresponding to the large decrease in the position of  the FSDP  in Q  can be expected  to  arise  from geometrical  changes (bond angles etc.) yielding voids in the structure. This recov-ered structure is not periodic and remains amorphous. This recovery of an amorphous material with a similar density to the initial crystal-line phase is an indication of a memory effect at the level of the local and intermediate range order. It is distinct from the memory effect re-ported in crystalline, non-porous AlPO4 berlinite, which was proposed to transform reversibly to an amorphous form under pressure29. Later studies by Raman spectroscopy30 and x-ray powder diffraction31 indi-cated  that  instead  the  high-pressure  form was  a  poorly-crystallized phase with a CrVO4 structure with Al in octahedral coordination, which retransformed to berlinite on decompression. Figure 3. Normalized intensity of diffraction signals (with re-spect to maximum values for single crystal and amorphous) of AlPO4-17 as a function of pressure (a). Position of the FSDP in Q  of  AlPO4-17  as  a  function  of  pressure  (b).  Data  for  silica glass28 are given for comparison.  Based  on  x-ray  diffraction,  the  unit  cell  volume  of  the  crystalline phase decreases by 32% between ambient pressure and 2.5 GPa. This can be compared with initial pore volume, which represents 38% of the total volume of the AlPO4-17 structure. The dimensions of the sample at 1.45 GPa, which was then predominantly amorphous, give a relative volume of 0.78 for the amorphous form. This is 8% lower than the rem-nant crystalline domains at the same pressure. Based on these results, the amorphous form can be expected to exhibit almost no porosity at 2.5 GPa. It can be noted that starting from this pressure, the position of the FSDP is similar to that of non-porous silica glass. The present  results  provide  a  coherent  overall  picture  of  a  direct transformation of a  single crystal  to an amorphous material. The re-tained shape of the crystal and the orientation of remnant crystal do-mains upon transformation are consistent with a direct transformation pathway. Single-crystal x-ray diffraction  indicates  the collapse of  the structure around the empty pores. The estimation of the density of the amorphous form provides evidence that the pressure-induced volume changes are reversible. This collapse of the structure and the observa-tion that the reversible volume change essentially corresponds to the initial porous volume of the crystal can be indirectly used to infer that the  transformation  mechanism  corresponds  to  pore  collapse  while keeping the network topology of the AlPO4 framework.  A memory ef-fect is observed in the amorphous form, which strongly expands on de-compression  returning  to  the  density  of  the  initial  crystalline  form without recovering long-range order. The amorphous form thus exhib-its a very high degree of flexibility. Such a new topologically ordered amorphous phase could approach a  low-entropy “perfect” glass with improved mechanical properties as compared to standard glasses.  ASSOCIATED CONTENT   Supporting Information Experimental details, additional figures and tables of crystallo-graphic data are supplied as Supporting Information. This ma-terial  is  available  free  of  charge  via  the  Internet  at http://pubs.acs.org.   Accession Codes CSD 2323675-2323684  contain  the  supplementary  crystallo-graphic  data  for  this  paper.  These  data  are  provided  free  of charge  by  the  joint  Cambridge  Crystallographic  Data  Centre and  Fachinformationszentrum  Karlsruhe  Access  Structures service. NNootteess  The authors declare no competing financial interest.  AAcckknnoowwlleeddggmmeenntt    The  synchrotron  X-ray  diffraction  experiments  were  per-formed at the Xpress beamline from Elettra Sincrotrone Trieste (proposal  number:  20225386). We  acknowledge  Elettra  Sin-crotrone Trieste for providing access to its synchrotron radia-tion facilities and for financial support under the IUS internal project.  RREEFFEERREENNCCEESS  (1)  Richet, P.; Gillet, P. Pressure-induced amorphization of minerals: a review. Eur. J. Mineral 1997, 9 (5), 907-933. (2)  Sharma,  S.  M.;  Sikka,  S.  K.  Pressure  induced amorphization of materials. Progress in Materials Science 1996, 40 (1), 1-77. (3)  Machon,  D.;  Meersman,  F.;  Wilding,  M.  C.;  Wilson,  M.; McMillan,  P.  F.  Pressure-induced  amorphization  and polyamorphism:  Inorganic  and  biochemical  systems. Progress  in Materials Science 2014, 61, 216-282. (4)  Mishima, O.; Calvert, L. D.; Whalley, E. 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Zeolites at high pressure: A review. Mineral. Mag. 2014, 78 (2), 267-291. (20)  Alabarse, F. G.; Silly, G.; Brubach, J. B.; Roy, P.; Haidoux, A.; Levelut, C.; Bantignies, J. L.; Kohara, S.; Le Floch, S.; Cambon, O.; Haines, J. Anomalous compressibility and amorphization in AlPO4-17, the oxide with the highest negative thermal expansion. J. Phys. Chem. C 2017, 121 (12), 6852-6863. (21)  Collings, I. E.; Goodwin, A. L. Metal-organic frameworks under pressure. J. Appl. Phys. 2019, 126 (18) 181101. (22)  Masai, H.; Kohara, S.; Wakihara, T.; Shibazaki, Y.; Onodera, Y.; Masuno, A.; Sukenaga, S.; Ohara, K.; Sakai, Y.; Haines, J.; Levelut, C.; Hebert, P.; Isambert, A.; Keen, D. A.; Azuma, M. Siliceous zeolite-derived topology of amorphous silica. Commun. Chem. 2023, 6 (1) 269. (23)  Attfield, M. P.; Sleight, A. W. Exceptional negative thermal expansion in AlPO4-17. Chem. Mater. 1998, 10 (7), 2013-2019. (24)  Murata, K.; Yokogawa, K.; Yoshino, H.; Klotz, S.; Munsch, P.;  Irizawa,  A.;  Nishiyama,  M.;  Iizuka,  K.;  Nanba,  T.;  Okada,  T.; Shiraga,  Y.;  Aoyama,  S.  Pressure  transmitting  medium  Daphne 7474 solidifying at 3.7 GPa at room temperature. Rev. Sci. Instrum. 2008, 79 (8), 085101. (25)  Birch,  F.  Equation  of  state  and  thermodynamic parameters of NaCl to 300-kbar in the high-temperature domain. J. Geophys. Res. 1986, 91 (B5), 4949-4954. (26)  Sowa, H.; Macavei, J.; Schulz, H. The crystal-structure of berlinite  AlPO4  at  high-pressure.  Z.  Kristallogr. 1990,  192  (1-2), 119-136. (27)  Alabarse,  F.  G.;  Baptiste,  B.;  Guarnelli,  Y.;  Joseph,  B.; Haines,  J.  Strongly  modified  mechanical  properties  and  phase transition  in  AlPO4-17  due  to  insertion  of  guest  species  at  high pressure. J. Phys. Chem. C 2023, 127 (29), 14528-14533. (28)  Inamura,  Y.;  Katayama,  Y.;  Utsumi,  W.;  Funakoshi,  K. Transformations in the intermediate-range structure of SiO2 glass under  high  pressure  and  temperature. Phys.  Rev.  Lett. 2004, 93, 015501 (29)  Kruger, M. B.; Jeanloz, R. Memory glass - an amorphous material formed from AlPO4. Science 1990, 249 (4969), 647-649. (30)  Gillet,  P.;  Badro,  J.;  Varrel,  B.;  McMillan,  P.  F.  High-pressure  behavior  in  alpha-AlPO4  -  amorphization  and  the memory-glass effect. Phys. Rev. B 1995, 51 (17), 11262-11269. (31)  Sharma, S. M.; Garg, N.; Sikka, S. K. High-pressure x-ray-diffraction study of α-AlPO4. Phys. Rev. B 2000, 62 (13), 8824-8827.   S1  Direct Single Crystal to Amorphous Transformation and Memory Effect in AlPO4-17. Frederico G. Alabarsea, Benoît Baptisteb, Yoann Guarnellib,  Yohei Onoderac, Shinji Koharac, and Julien Hainesd,*  aElettra Sincrotrone Trieste, Trieste 34149, Italy  bInstitut de Minéralogie, de Physique des Matériaux et de Cosmochimie, (IMPMC) UMR 7590 CNRS – Sorbonne Université – IRD – MNHN, 4 place Jussieu, 75252 Paris Cedex 5, France  cCenter for Basic Research on Materials, National Institute for Materials Science,  1-2-1 Sengen, Tsukuba, Ibaraki 305-0047, Japan.  dInstitut Charles Gerhardt Montpellier, Université de Montpellier, CNRS, ENSCM, 34293 Montpellier, France  *E-mail: Julien.haines@umontpellier.fr  Experimental Synthesis. Single crystals of hydrated AlPO4-17 with maximum dimensions of 250 × 70 × 70 μm3 were synthesized under hydrothermal conditions from aluminum triisopropoxide and phosphoric acid using N,N,N′,N′-tetramethyl-1,6-hexanediamine as a structure directing agent as described previously1,2. The crystals were calcined in air at 500 °C for 24 h. High-pressure experiment. Two AlPO4-17 single crystals (dimensions 154 × 76 × 76 μm3 and 110 × 35 × 35 μm3) were placed in 400 µm diameter and a 150 µm thick, stainless steel gasket along with a ruby pressure calibrant in a membrane diamond anvil cell (DAC) with 800 µm culets and an opening angle of 80°. The DAC was placed in a cryogenic gas loading system and the sample was dehydrated for 1h30 at 110 °C under vacuum (4 Pa). DAPHNE7474 oil3 was then added. Crystal dimensions were obtained from analysis of optical images. High-pressure x-ray diffraction. X-ray diffraction measurements (=0.4956 Å) under pressure were performed with an 80 µm beam on the Xpress beamline equipped with a PILATUS3 S 6M (DECTRIS) detector at the Elettra Sincrotrone Trieste (Trieste, Italy). The detector was placed at 255 mm from the sample. The pressure was measured based on the shift in the R1 fluorescence line of ruby4. Diffraction data were collected from the AlPO4-17 single crystals using phi scans from –38° to +37°. Data reduction was performed with CrysalisPro 1.171.43.92a (Rigaku OD, 2023). The crystal structure was refined using Shelxl-2017/1295 with the OLEX6 interface. Data are given for the larger crystal as they are of better quality due to higher measured intensities. The void volume was calculated with Platon Squeeze7 using the OLEX interface. Crystal structures plotted using Vesta8. Equation of state parameters were calculated with EosFit7_GUI9. High energy X-ray total scattering. Data from the amorphous powder sample recovered from 5 GPa1 in a belt-type apparatus were obtained using the two-axis, horizontal diffractometer built for liquid and glass samples on the bending magnet beamline BL04B2 with 61.6 keV X-rays at the SPring-8 synchrotron as described previously1. The pair distribution function was obtained in the form of the total radial distribution function G(r) by direct Fourier transformation of the total scattering data S(Q) obtained up to a maximum Q of 20 Å−1. The details of experiment and standard data analysis are described elsewhere10-11.  S2  References  (1) Haines, J.; Levelut, C.; Isambert, A.; Hebert, P.; Kohara, S.; Keen, D. A.; Hammouda, T.; Andrault, D. Topologically ordered amorphous silica obtained from the collapsed siliceous zeolite, silicalite-1-F: a step toward "perfect" glasses. J. Am. Chem. Soc. 2009, 131 (34), 12333-12338.. (2) Tuel, A.; Lorentz, C.; Gramlich, V.; Baerlocher, AIPO-ERI, an aluminophosphate with the ERI framework topology: characterization and structure of the as-made and calcined rehydrated forms. C. Cr. Chim. 2005, 8, 531-540.  (3) Murata, K.; Yokogawa, K.; Yoshino, H.; Klotz, S.; Munsch, P.; Irizawa, A.; Nishiyama, M.; Iizuka, K.; Nanba, T.; Okada, T.; Shiraga, Y.; Aoyama, S. Pressure transmitting medium Daphne 7474 solidifying at 3.7 GPa at room temperature. Rev. Sci. Instrum. 2008, 79, 085101. (4) Dewaele, A.; Torrent, M.; Loubeyre, P.; Mezouar, M. Compression curves of transition metals in the Mbar range: Experiments and projector augmented-wave calculations.  Phys. Rev. B 2008, 78, 104102. (5) Sheldrick, G. M. Crystal structure refinement with SHELXL Acta Crystallogr. C 2015, 71, 3-8. (6) Dolomanov, O. V.; Bourhis, L. J.; Gildea, R. J.; Howard, J. A. K.; Puschmann, H. OLEX2: a complete structure solution, refinement and analysis program.  J. Appl. Crystallogr. 2009, 42, 339-241. (7) Spek, A. L. PLATON SQUEEZE: a tool for the calculation of the disordered solvent contribution to the calculated structure factors. Acta Crystallogr. C 2015, 71, 9-18. (8) Momma, K.; Izumi, F. VESTA 3 for three-dimensional visualization of crystal, volumetric and morphology data.  J. Appl. Crystallogr. 2011, 44, 1272-1276. (9) Gonzalez-Platas, J.; Alvaro, M.; Nestola, F.; Angel, R. J. Appl. Crystallogr. 2016, 49, 1377-1382. (10) Isshiki, M.; Ohishi, Y.; Goto, S.; Takeshita, K.; Ishikawa, T. High-energy X-ray diffraction beamline: BL04B2 at SPring-8. Nucl. Instrum. Meth. A 2001, 467, 663-666. (11) Kohara, S.; Itou, M.; Suzuya, K.; Inamura, Y.; Sakurai, Y.; Ohishi, Y.; Takata, M. Structural studies of disordered materials using high-energy x-ray diffraction from ambient to extreme conditions.  J. Phys.-Condens. Mat. 2007, 19, 506101. (12) Hashimoto, H.; Onodera, Y.; Tahara, S.; Kohara, S.; Yazawa, K.; Segawa, H.; Murakami, M.; Ohara, K. . Structure of alumina glass. Sci. Rep. 2022, 12, 516. (13) Hoppe, U.; Kranold, R.; Barz, A.; Stachel, D.; Neuefeind, The structure of vitreous P2O5 studied by high-energy X-ray diffraction. Solid State Commun. 2000, 115, 559-562.  S3   Figure S1. Cell parameters a of single-crystal AlPO4-17 as a function of pressure (a). Cell parameters c of single-crystal AlPO4-17 as a function of pressure (b). The solid lines represent 2nd order Birch-Murnaghan EOS fits to the data up to the onset of amorphization at 0.6 GPa giving the following compressibilities along a (0.0081(2) GPa-1) and c (0.0111(5) GPa-1). S4   Figure S2. Relative unit cell volume of single-crystal AlPO4-17 as a function of pressure (a). Relative porous volume of single-crystal AlPO4-17 as a function of pressure (b). The solid lines represent 2nd order Birch-Murnaghan EOS fits to the data up to the onset of amorphization at 0.6 GPa giving the following bulk moduli for the unit cell, 36(1) GPa, and the pores, 14(4) GPa.      S5   Figure S3. In-plane (ip-xy) and out-of-plane (oop) Al-O-P angles in the 4MR and 6MR of AlPO4-17 as a function of pressure. Figure S4.  (h0l) Reciprocal space reconstruction for AlPO4-17 at 0.97 GPa. Arrows indicate the principal rows of superlattice reflections. 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4140150160170<Al-O-P (°)P(GPa)6MR ip4MR ip4MR oop4MR ip4MR ip4MR oop4MR oopericanD6MRcanS6   Figure S5.  Structure factors S(Q) (a), reduced pair distribution functions G(r) (b) and detail of the low r region of G(r) (c) for amorphous AlPO4-17 recovered from 5 GPa1, Al2O312 and P2O513 glasses.   Figure S6. Reduced pair distribution function G(r) for amorphous AlPO4-17 recovered from 5 GPa1 showing the determination of the initial slope used to estimate the sample density (a) and dependence of 2 on the fitted density (b).  S7  Table S1. Hexagonal unit cell parameters of an AlPO4-17 single crystal as a function of pressure. P(GPa) a(Å) c(Å) V(Å3) 0.0001 13.0758(9) 15.3189(4) 2268.3(3) 0.09 13.0641(8) 15.2968(5) 2260.9(3) 0.189 13.0556(9) 15.285(5) 2256.3(3) 0.291 13.0443(10) 15.2662(5) 2249.6(3) 0.414 13.0318(11) 15.2511(6) 2243.1(4) 0.549 13.0191(11) 15.2329(6) 2236.0(4) 0.723 12.9981(13) 15.2105(7) 2225.5(5) 0.834 12.9715(14) 15.1870(7) 2213.5(5) 0.97 12.885(3) 15.1515(11) 2178.7(10) 1.11 12.749(5) 15.123(2) 2129(2) 1.16 12.64(3) 15.121(8) 2093(10) 1.454* 12.27(2) 15.136(15) 1973(6) 2.03* 11.15(9) 15.48(3) 1667(20) 2.481* 10.89 15.31 1573 *Cell parameters corresponding to the strongest diffracting remanent crystalline domain in the amorphous matrix. Other minor domains exhibited a distribution of cell parameters due to stress gradients as the external pressure in the surrounding fluid is transmitted by the rigid amorphous matrix surrounding the crystallites. S8   Table S2 Crystal data and structure refinement for AlPO4-17 at 0.1 MPa Identification code 17hyd_SC5 Empirical formula O4AlP Formula weight 121.95 Temperature/K 293(2) Crystal system hexagonal Space group P63/m a/Å 13.0758(9) b/Å 13.0758(9) c/Å 15.3189(4) α/° 90 β/° 90 γ/° 120 Volume/Å3 2268.3(3) Z 18 ρcalcg/cm3 1.607 μ/mm-1 0.223 F(000) 1080.0 Crystal size/mm3 0.154 × 0.74 × 0.74 Radiation synchrotron (λ = 0.49555) 2Θ range for data collection/° 3.708 to 38.566 Index ranges -8 ≤ h ≤ 13, -13 ≤ k ≤ 8, -20 ≤ l ≤ 20 Reflections collected 5001 Independent reflections 1406 [Rint = 0.0278, Rsigma = 0.0305] Data/restraints/parameters 1406/0/88 Goodness-of-fit on F2 1.094 Final R indexes [I>=2σ (I)] R1 = 0.0384, wR2 = 0.1029 Final R indexes [all data] R1 = 0.0492, wR2 = 0.1076 Largest diff. peak/hole / e Å-3 0.32/-0.33     Table S3 Fractional Atomic Coordinates (×104) and Equivalent Isotropic Displacement Parameters (Å2×103) for AlPO4-17 at 0.1 MPa. Ueq is defined as 1/3 of the trace of the orthogonalised UIJ tensor. Atom x y z U(eq) P1 9973.9(6) 2373.1(6) 1013.3(4) 18.8(2) P2 5747.3(8) 9080.5(9) 2500 17.4(2) Al2 918.7(10) 4232.2(10) 2500 17.1(3) Al1 7610.1(7) 9974.7(7) 1006.5(4) 18.3(2) O1 229(2) 3416.5(19) 1586.2(11) 29.1(5) S9  Table S3 Fractional Atomic Coordinates (×104) and Equivalent Isotropic Displacement Parameters (Å2×103) for AlPO4-17 at 0.1 MPa. Ueq is defined as 1/3 of the trace of the orthogonalised UIJ tensor. Atom x y z U(eq) O1B 6464.0(19) 9694(2) 1689.0(11) 30.8(5) O2 910(2) 2016(2) 1140.8(13) 35.0(5) O3 1326.3(19) 2540(2) 6261.2(11) 29.7(5) O4 2769(2) 37(2) 10066.6(10) 32.8(5) O5 2374(3) 4586(3) 2500 32.5(7) O6 4645(2) 9170(3) 2500 26.2(6)   Table S4 Anisotropic Displacement Parameters (Å2×103) for AlPO4-17 at 0.1 MPa. The Anisotropic displacement factor exponent takes the form: -2π2[h2a*2U11+2hka*b*U12+…]. Atom U11 U22 U33 U23 U13 U12 P1 17.3(4) 19.6(4) 17.2(3) -2.7(2) -0.5(2) 7.3(3) P2 15.4(5) 19.0(5) 18.3(4) 0 0 8.8(4) Al2 19.4(6) 15.2(6) 16.8(4) 0 0 8.7(5) Al1 19.0(4) 17.8(4) 16.2(3) 0.6(2) 2.2(2) 7.7(3) O1 36.1(13) 23.9(11) 23.7(8) -6.4(7) -2.4(7) 12.3(10) O1B 26.1(12) 37.0(13) 27.7(9) 5.6(8) 8.6(7) 14.6(11) O2 27.2(13) 36.6(14) 43.8(11) 2.7(9) 2.0(8) 17.9(11) O3 24.4(12) 36.1(14) 34.5(9) -7.4(8) -4.6(7) 19.4(11) O4 38.6(13) 44.6(14) 19.7(8) 2.2(7) 2.4(7) 24.1(12) O5 23.5(17) 25.4(18) 49.2(16) 0 0 12.6(14) O6 20.4(15) 33.4(18) 29.5(12) 0 0 16.8(14)   Table S5 Bond Lengths for AlPO4-17 at 0.1 MPa. Atom Atom Length/Å   Atom Atom Length/Å P1 O11 1.513(2)   Al2 O14 1.7172(19) P1 O21 1.525(2)   Al2 O1 1.7172(19) P1 O32 1.518(2)   Al2 O5 1.720(3) P1 O43 1.5264(18)   Al2 O65 1.686(3) P2 O1B 1.5211(19)   Al1 O1B 1.710(2) P2 O1B4 1.5212(19)   Al1 O25 1.723(2) P2 O55 1.519(3)   Al1 O36 1.709(2) P2 O6 1.503(3)   Al1 O47 1.7149(18) 11+X,+Y,+Z; 21-Y+X,+X,-1/2+Z; 31-Y,+X-Y,-1+Z; 4+X,+Y,1/2-Z; 51-Y,1+X-Y,+Z; 61-Y+X,1+X,-1/2+Z; 71-X,1-Y,1-Z   S10  Table S6 Bond Angles for AlPO4-17 at 0.1 MPa. Atom Atom Atom Angle/˚   Atom Atom Atom Angle/˚ O11 P1 O21 110.69(12)   O65 Al2 O1 109.32(10) O11 P1 O32 109.44(12)   O65 Al2 O5 109.93(16) O11 P1 O43 107.80(13)   O1B Al1 O25 109.21(11) O21 P1 O43 110.38(12)   O1B Al1 O36 108.72(11) O32 P1 O21 107.93(13)   O1B Al1 O47 111.45(12) O32 P1 O43 110.61(12)   O36 Al1 O25 110.07(12) O1B P2 O1B4 109.53(18)   O36 Al1 O47 109.56(10) O1B4 P2 O55 110.20(11)   O47 Al1 O25 107.84(11) O1B P2 O55 110.20(11)   P18 O1 Al2 147.53(15) O6 P2 O1B4 108.71(11)   P2 O1B Al1 148.79(16) O6 P2 O1B 108.71(11)   P18 O2 Al19 146.99(17) O6 P2 O55 109.47(17)   P110 O3 Al111 149.42(13) O14 Al2 O1 109.22(16)   P112 O4 Al17 145.27(17) O14 Al2 O5 109.52(10)   P29 O5 Al2 152.1(2) O1 Al2 O5 109.52(10)   P2 O6 Al29 172.7(2) O65 Al2 O14 109.32(10)           11+X,+Y,+Z; 21-Y+X,+X,-1/2+Z; 31-Y,+X-Y,-1+Z; 4+X,+Y,1/2-Z; 51-Y,1+X-Y,+Z; 61-Y+X,1+X,-1/2+Z; 71-X,1-Y,1-Z; 8-1+X,+Y,+Z; 9+Y-X,1-X,+Z; 10+Y,1-X+Y,1/2+Z; 11-1+Y,-X+Y,1/2+Z; 121+Y-X,1-X,1+Z    Table S7 Crystal data and structure refinement for AlPO4-17 at 0.09 GPa. Identification code 17_SC05_P1b Empirical formula O4AlP Formula weight 121.95 Temperature/K 293(2) Crystal system hexagonal Space group P63/m a/Å 13.0641(8) b/Å 13.0641(8) c/Å 15.2968(5) α/° 90 β/° 90 γ/° 120 Volume/Å3 2260.9(3) Z 18 ρcalcg/cm3 1.612 μ/mm-1 0.224 F(000) 1080.0 Crystal size/mm3 ? × ? × ? Radiation synchrotron (λ = 0.49555) S11  2Θ range for data collection/° 3.712 to 38.512 Index ranges -8 ≤ h ≤ 13, -12 ≤ k ≤ 7, -20 ≤ l ≤ 20 Reflections collected 4770 Independent reflections 1390 [Rint = 0.0337, Rsigma = 0.0395] Data/restraints/parameters 1390/0/88 Goodness-of-fit on F2 1.140 Final R indexes [I>=2σ (I)] R1 = 0.0469, wR2 = 0.1195 Final R indexes [all data] R1 = 0.0656, wR2 = 0.1263 Largest diff. peak/hole / e Å-3 0.48/-0.36     Table S8 Fractional Atomic Coordinates (×104) and Equivalent Isotropic Displacement Parameters (Å2×103) for AlPO4-17 at 0.09 GPa. Ueq is defined as 1/3 of the trace of the orthogonalised UIJ tensor. Atom x y z U(eq) P1 9972.5(8) 2371.0(8) 1014.2(4) 14.2(3) P2 5747.1(11) 9080.8(11) 2500 12.8(3) Al2 919.4(12) 4233.3(12) 2500 12.1(3) Al1 7611.1(9) 9974.3(9) 1007.4(5) 13.9(3) O1 227(2) 3419(2) 1585.6(13) 25.5(6) O1B 6460(2) 9692(3) 1688.7(13) 26.8(6) O2 909(2) 2015(3) 1142.8(16) 31.2(7) O3 1326(2) 2541(2) 6265.3(14) 24.8(6) O4 2767(3) 38(2) 10066.8(13) 28.8(7) O5 2377(3) 4586(3) 2500 29.1(9) O6 4645(3) 9170(3) 2500 22.8(8)   Table S9 Anisotropic Displacement Parameters (Å2×103) for AlPO4-17 at 0.09 GPa. The Anisotropic displacement factor exponent takes the form: -2π2[h2a*2U11+2hka*b*U12+…]. Atom U11 U22 U33 U23 U13 U12 P1 11.7(5) 12.8(5) 16.0(4) -2.8(3) -0.6(3) 4.5(4) P2 7.9(6) 12.7(7) 18.0(5) 0 0 5.3(5) Al2 12.3(8) 8.3(8) 16.0(5) 0 0 5.4(6) Al1 13.3(6) 12.5(6) 14.3(4) 0.6(3) 2.1(3) 5.2(5) O1 32.5(17) 18.9(15) 21.8(10) -5.1(8) -2.0(9) 10.3(13) O1B 18.7(15) 33.7(17) 26.5(11) 6.5(10) 10.2(9) 12.1(13) O2 21.0(17) 28.1(18) 45.5(14) 4.2(11) 3.6(10) 13.1(14) O3 15.9(14) 28.4(17) 34.8(11) -7.9(10) -4.5(9) 14.7(13) O4 34.3(17) 38.1(18) 17.4(10) 0.8(9) 1.6(9) 20.7(15) O5 19(2) 19(2) 50(2) 0 0 10.5(18) S12  Table S9 Anisotropic Displacement Parameters (Å2×103) for AlPO4-17 at 0.09 GPa. The Anisotropic displacement factor exponent takes the form: -2π2[h2a*2U11+2hka*b*U12+…]. Atom U11 U22 U33 U23 U13 U12 O6 16(2) 29(2) 28.9(15) 0 0 15.1(18)   Table S10 Bond Lengths for AlPO4-17 at 0.09 GPa. Atom Atom Length/Å   Atom Atom Length/Å P1 O11 1.514(2)   Al1 O25 1.721(3) P1 O21 1.523(3)   Al1 O36 1.708(3) P1 O32 1.517(3)   Al1 O47 1.714(2) P1 O43 1.525(2)   O1 P18 1.514(2) P2 O1B 1.517(2)   O2 P18 1.523(3) P2 O1B4 1.517(2)   O2 Al19 1.721(3) P2 O55 1.515(4)   O3 P110 1.517(3) P2 O6 1.501(3)   O3 Al111 1.708(3) Al2 O14 1.716(2)   O4 P112 1.525(2) Al2 O1 1.716(2)   O4 Al17 1.714(2) Al2 O5 1.721(4)   O5 P29 1.515(4) Al2 O65 1.684(4)   O6 Al29 1.684(4) Al1 O1B 1.711(2)         11+X,+Y,+Z; 21-Y+X,+X,-1/2+Z; 31-Y,+X-Y,-1+Z; 4+X,+Y,1/2-Z; 51-Y,1+X-Y,+Z; 61-Y+X,1+X,-1/2+Z; 71-X,1-Y,1-Z; 8-1+X,+Y,+Z; 9+Y-X,1-X,+Z; 10+Y,1-X+Y,1/2+Z; 11-1+Y,-X+Y,1/2+Z; 121+Y-X,1-X,1+Z   Table S11 Bond Angles for AlPO4-17 at 0.09 GPa. Atom Atom Atom Angle/˚   Atom Atom Atom Angle/˚ O11 P1 O21 110.73(15)   O65 Al2 O1 109.20(12) O11 P1 O32 109.34(14)   O65 Al2 O5 110.02(19) O11 P1 O43 107.63(16)   O1B Al1 O25 109.19(14) O21 P1 O43 110.38(15)   O1B Al1 O46 111.33(14) O32 P1 O21 108.00(15)   O37 Al1 O1B 108.67(13) O32 P1 O43 110.77(14)   O37 Al1 O25 110.12(14) O1B4 P2 O1B 109.8(2)   O37 Al1 O46 109.69(13) O55 P2 O1B4 110.16(14)   O46 Al1 O25 107.84(13) O55 P2 O1B 110.16(14)   P18 O1 Al2 147.23(19) O6 P2 O1B 108.63(13)   P2 O1B Al1 148.63(19) O6 P2 O1B4 108.63(13)   P18 O2 Al19 147.0(2) O6 P2 O55 109.4(2)   P110 O3 Al111 149.05(15) O14 Al2 O1 109.20(19)   P112 O4 Al16 145.4(2) O14 Al2 O5 109.60(12)   P29 O5 Al2 152.2(3) O1 Al2 O5 109.60(12)   P2 O6 Al29 172.7(3) O65 Al2 O14 109.20(12)           S13  11+X,+Y,+Z; 21-Y+X,+X,-1/2+Z; 31-Y,+X-Y,-1+Z; 4+X,+Y,1/2-Z; 51-Y,1+X-Y,+Z; 61-X,1-Y,1-Z; 71-Y+X,1+X,-1/2+Z; 8-1+X,+Y,+Z; 9+Y-X,1-X,+Z; 10+Y,1-X+Y,1/2+Z; 11-1+Y,-X+Y,1/2+Z; 121+Y-X,1-X,1+Z    Table S12 Crystal data and structure refinement for AlPO4-17 at 0.189 GPa. Identification code 17_SC05_P2 Empirical formula O4AlP Formula weight 121.95 Temperature/K 293(2) Crystal system hexagonal Space group P63/m a/Å 13.0556(9) b/Å 13.0556(9) c/Å 15.2850(5) α/° 90 β/° 90 γ/° 120 Volume/Å3 2256.3(3) Z 18 ρcalcg/cm3 1.616 μ/mm-1 0.224 F(000) 1080.0 Crystal size/mm3 ? × ? × ? Radiation synchrotron (λ = 0.49555) 2Θ range for data collection/° 3.716 to 38.54 Index ranges -8 ≤ h ≤ 13, -12 ≤ k ≤ 7, -20 ≤ l ≤ 20 Reflections collected 4694 Independent reflections 1388 [Rint = 0.0337, Rsigma = 0.0393] Data/restraints/parameters 1388/0/88 Goodness-of-fit on F2 1.123 Final R indexes [I>=2σ (I)] R1 = 0.0494, wR2 = 0.1195 Final R indexes [all data] R1 = 0.0687, wR2 = 0.1269 Largest diff. peak/hole / e Å-3 0.47/-0.34     Table S13 Fractional Atomic Coordinates (×104) and Equivalent Isotropic Displacement Parameters (Å2×103) for AlPO4-17 at 0.189 GPa. Ueq is defined as 1/3 of the trace of the orthogonalised UIJ tensor. Atom x y z U(eq) P1 9973.1(8) 2371.1(8) 1014.3(5) 15.0(3) S14  Table S13 Fractional Atomic Coordinates (×104) and Equivalent Isotropic Displacement Parameters (Å2×103) for AlPO4-17 at 0.189 GPa. Ueq is defined as 1/3 of the trace of the orthogonalised UIJ tensor. Atom x y z U(eq) P2 5746.2(11) 9080.4(11) 2500 13.8(3) Al2 920.8(13) 4232.4(13) 2500 13.1(3) Al1 7611.0(10) 9973.9(9) 1008.1(5) 14.9(3) O1 226(3) 3418(2) 1585.2(14) 26.7(7) O1B 6460(3) 9694(3) 1688.5(15) 28.4(7) O2 908(3) 2017(3) 1143.6(17) 32.5(7) O3 1326(2) 2544(3) 6266.5(15) 26.5(6) O4 2764(3) 38(3) 10067.3(14) 30.5(7) O5 2377(3) 4586(4) 2500 30.7(9) O6 4644(3) 9171(4) 2500 23.6(8)   Table S14 Anisotropic Displacement Parameters (Å2×103) for AlPO4-17 at 0.189 GPa. The Anisotropic displacement factor exponent takes the form: -2π2[h2a*2U11+2hka*b*U12+…]. Atom U11 U22 U33 U23 U13 U12 P1 12.6(5) 14.0(5) 16.1(4) -2.8(3) -0.4(3) 4.9(4) P2 9.7(7) 13.8(7) 18.2(5) 0 0 6.2(6) Al2 13.9(8) 9.5(8) 16.7(6) 0 0 6.4(7) Al1 14.2(6) 14.3(6) 14.6(4) 0.5(3) 2.4(3) 6.0(5) O1 36.2(18) 17.4(15) 22.6(11) -5.9(9) -2.1(10) 10.5(14) O1B 20.1(16) 35.1(18) 29.1(13) 6.1(11) 10.5(10) 13.2(14) O2 22.9(18) 31.2(19) 45.8(15) 4.6(12) 3.9(11) 15.3(15) O3 17.7(16) 33.4(18) 34.5(12) -8.3(11) -5.2(10) 17.4(14) O4 36.6(18) 41.4(19) 18.1(11) 1.7(10) 2.9(10) 22.9(16) O5 18(2) 20(2) 53(2) 0 0 8.5(19) O6 14(2) 32(2) 31.3(16) 0 0 16.4(19)   Table S15 Bond Lengths for AlPO4-17 at 0.189 GPa. Atom Atom Length/Å   Atom Atom Length/Å P1 O11 1.513(3)   Al1 O25 1.721(3) P1 O21 1.519(3)   Al1 O36 1.706(3) P1 O32 1.519(3)   Al1 O47 1.713(2) P1 O43 1.522(2)   O1 P18 1.513(3) P2 O1B 1.517(2)   O2 P18 1.519(3) P2 O1B4 1.517(2)   O2 Al19 1.721(3) P2 O55 1.514(4)   O3 P110 1.519(3) P2 O6 1.502(4)   O3 Al111 1.706(3) Al2 O14 1.715(2)   O4 P112 1.522(2) S15  Table S15 Bond Lengths for AlPO4-17 at 0.189 GPa. Atom Atom Length/Å   Atom Atom Length/Å Al2 O1 1.715(2)   O4 Al17 1.713(2) Al2 O5 1.717(4)   O5 P29 1.514(4) Al2 O65 1.683(4)   O6 Al29 1.683(4) Al1 O1B 1.710(3)         11+X,+Y,+Z; 21-Y+X,+X,-1/2+Z; 31-Y,+X-Y,-1+Z; 4+X,+Y,1/2-Z; 51-Y,1+X-Y,+Z; 61-Y+X,1+X,-1/2+Z; 71-X,1-Y,1-Z; 8-1+X,+Y,+Z; 9+Y-X,1-X,+Z; 10+Y,1-X+Y,1/2+Z; 11-1+Y,-X+Y,1/2+Z; 121+Y-X,1-X,1+Z   Table S16 Bond Angles for AlPO4-17 at 0.189 GPa. Atom Atom Atom Angle/˚   Atom Atom Atom Angle/˚ O11 P1 O21 110.75(16)   O65 Al2 O1 109.06(13) O11 P1 O32 109.18(15)   O65 Al2 O5 110.1(2) O11 P1 O43 107.75(16)   O1B Al1 O25 109.25(15) O21 P1 O43 110.34(16)   O1B Al1 O46 111.44(15) O32 P1 O21 108.13(16)   O37 Al1 O1B 108.51(14) O32 P1 O43 110.69(15)   O37 Al1 O25 110.30(15) O1B4 P2 O1B 109.7(2)   O37 Al1 O46 109.61(14) O55 P2 O1B4 110.22(15)   O46 Al1 O25 107.74(14) O55 P2 O1B 110.22(15)   P18 O1 Al2 147.1(2) O6 P2 O1B 108.59(14)   P2 O1B Al1 148.5(2) O6 P2 O1B4 108.59(14)   P18 O2 Al19 147.1(2) O6 P2 O55 109.5(2)   P110 O3 Al111 148.88(17) O14 Al2 O1 109.2(2)   P112 O4 Al16 145.7(2) O14 Al2 O5 109.73(13)   P29 O5 Al2 152.2(3) O1 Al2 O5 109.73(13)   P2 O6 Al29 172.6(3) O65 Al2 O14 109.06(13)           11+X,+Y,+Z; 21-Y+X,+X,-1/2+Z; 31-Y,+X-Y,-1+Z; 4+X,+Y,1/2-Z; 51-Y,1+X-Y,+Z; 61-X,1-Y,1-Z; 71-Y+X,1+X,-1/2+Z; 8-1+X,+Y,+Z; 9+Y-X,1-X,+Z; 10+Y,1-X+Y,1/2+Z; 11-1+Y,-X+Y,1/2+Z; 121+Y-X,1-X,1+Z   Table S17 Crystal data and structure refinement for AlPO4-17 at 0.291 GPa. Identification code 17_SC05_P3 Empirical formula O4AlP Formula weight 121.95 Temperature/K 293(2) Crystal system hexagonal Space group P63/m a/Å 13.0443(10) b/Å 13.0443(10) S16  c/Å 15.2662(5) α/° 90 β/° 90 γ/° 120 Volume/Å3 2249.6(3) Z 18 ρcalcg/cm3 1.620 μ/mm-1 0.225 F(000) 1080.0 Crystal size/mm3 ? × ? × ? Radiation synchrotron (λ = 0.49555) 2Θ range for data collection/° 3.72 to 38.58 Index ranges -8 ≤ h ≤ 13, -12 ≤ k ≤ 7, -20 ≤ l ≤ 20 Reflections collected 4677 Independent reflections 1392 [Rint = 0.0358, Rsigma = 0.0459] Data/restraints/parameters 1392/0/88 Goodness-of-fit on F2 1.077 Final R indexes [I>=2σ (I)] R1 = 0.0584, wR2 = 0.1444 Final R indexes [all data] R1 = 0.0824, wR2 = 0.1539 Largest diff. peak/hole / e Å-3 0.54/-0.46     Table S18 Fractional Atomic Coordinates (×104) and Equivalent Isotropic Displacement Parameters (Å2×103) for AlPO4-17 at 0.291 GPa. Ueq is defined as 1/3 of the trace of the orthogonalised UIJ tensor. Atom x y z U(eq) P1 9972.3(10) 2371.1(10) 1015.4(6) 17.5(3) P2 5745.1(13) 9079.2(14) 2500 15.9(4) Al2 921.3(16) 4233.6(15) 2500 14.5(4) Al1 7611.0(11) 9973.2(11) 1009.1(7) 17.1(4) O1 228(3) 3424(3) 1583.5(18) 30.9(8) O1B 6457(3) 9692(3) 1687.1(18) 30.7(8) O2 904(3) 2011(3) 1146(2) 35.3(9) O3 1329(3) 2548(3) 6269.4(18) 29.3(8) O4 2765(3) 38(3) 10066.9(17) 33.7(9) O5 2380(4) 4591(4) 2500 33.4(11) O6 4644(4) 9176(4) 2500 26.1(10)   S17  Table S19 Anisotropic Displacement Parameters (Å2×103) for AlPO4-17 at 0.291 GPa. The Anisotropic displacement factor exponent takes the form: -2π2[h2a*2U11+2hka*b*U12+…]. Atom U11 U22 U33 U23 U13 U12 P1 16.5(7) 16.3(6) 17.9(5) -2.9(4) -0.3(3) 6.9(5) P2 10.3(8) 17.7(9) 20.1(6) 0 0 7.5(7) Al2 15.6(10) 9.9(9) 18.0(7) 0 0 6.3(8) Al1 16.0(7) 16.4(8) 16.6(5) 0.9(4) 2.5(4) 6.4(6) O1 39(2) 24(2) 25.6(14) -6.4(11) -1.2(12) 12.2(17) O1B 23(2) 37(2) 31.2(16) 6.5(13) 10.8(12) 14.0(17) O2 23(2) 35(2) 49.3(19) 5.3(15) 4.4(14) 15.2(18) O3 21.6(19) 35(2) 37.8(15) -10.5(13) -6.7(12) 18.9(17) O4 39(2) 47(2) 19.5(14) 1.8(12) 2.2(11) 24.8(19) O5 18(3) 20(3) 60(3) 0 0 8(2) O6 22(3) 35(3) 34(2) 0 0 24(2)   Table S20 Bond Lengths for AlPO4-17 at 0.291 GPa. Atom Atom Length/Å   Atom Atom Length/Å P1 O11 1.514(3)   Al1 O25 1.723(4) P1 O21 1.519(4)   Al1 O36 1.707(3) P1 O32 1.517(3)   Al1 O47 1.712(3) P1 O43 1.523(3)   O1 P18 1.514(3) P2 O1B4 1.516(3)   O2 P18 1.519(4) P2 O1B 1.516(3)   O2 Al19 1.723(4) P2 O55 1.512(5)   O3 P110 1.517(3) P2 O6 1.504(4)   O3 Al111 1.707(3) Al2 O1 1.713(3)   O4 P112 1.523(3) Al2 O14 1.713(3)   O4 Al17 1.712(3) Al2 O5 1.718(5)   O5 P29 1.512(5) Al2 O65 1.677(4)   O6 Al29 1.677(4) Al1 O1B 1.709(3)         11+X,+Y,+Z; 21-Y+X,+X,-1/2+Z; 31-Y,+X-Y,-1+Z; 4+X,+Y,1/2-Z; 51-Y,1+X-Y,+Z; 61-Y+X,1+X,-1/2+Z; 71-X,1-Y,1-Z; 8-1+X,+Y,+Z; 9+Y-X,1-X,+Z; 10+Y,1-X+Y,1/2+Z; 11-1+Y,-X+Y,1/2+Z; 121+Y-X,1-X,1+Z   Table S21 Bond Angles for AlPO4-17 at 0.291 GPa. Atom Atom Atom Angle/˚   Atom Atom Atom Angle/˚ O11 P1 O21 111.0(2)   O65 Al2 O14 108.75(16) O11 P1 O32 109.21(18)   O65 Al2 O5 110.2(2) O11 P1 O43 107.4(2)   O1B Al1 O25 109.44(18) O21 P1 O43 110.47(19)   O1B Al1 O46 111.18(18) O32 P1 O21 108.0(2)   O37 Al1 O1B 108.45(17) O32 P1 O43 110.78(19)   O37 Al1 O25 110.23(19) S18  Table S21 Bond Angles for AlPO4-17 at 0.291 GPa. Atom Atom Atom Angle/˚   Atom Atom Atom Angle/˚ O1B P2 O1B4 109.9(3)   O37 Al1 O46 109.64(17) O55 P2 O1B 110.32(18)   O46 Al1 O25 107.90(17) O55 P2 O1B4 110.32(18)   P18 O1 Al2 146.7(2) O6 P2 O1B4 108.33(17)   P2 O1B Al1 148.2(2) O6 P2 O1B 108.33(17)   P18 O2 Al19 146.6(3) O6 P2 O55 109.6(3)   P110 O3 Al111 148.6(2) O1 Al2 O14 109.5(3)   P112 O4 Al16 145.6(3) O1 Al2 O5 109.82(16)   P29 O5 Al2 151.9(4) O14 Al2 O5 109.82(16)   P2 O6 Al29 172.1(3) O65 Al2 O1 108.75(16)           11+X,+Y,+Z; 21-Y+X,+X,-1/2+Z; 31-Y,+X-Y,-1+Z; 4+X,+Y,1/2-Z; 51-Y,1+X-Y,+Z; 61-X,1-Y,1-Z; 71-Y+X,1+X,-1/2+Z; 8-1+X,+Y,+Z; 9+Y-X,1-X,+Z; 10+Y,1-X+Y,1/2+Z; 11-1+Y,-X+Y,1/2+Z; 121+Y-X,1-X,1+Z    Table S22 Crystal data and structure refinement for AlPO4-17 at 0.414 GPa. Identification code 17_SC05_P4 Empirical formula O4AlP Formula weight 121.95 Temperature/K 293(2) Crystal system hexagonal Space group P63/m a/Å 13.0318(11) b/Å 13.0318(11) c/Å 15.2511(6) α/° 90 β/° 90 γ/° 120 Volume/Å3 2243.1(4) Z 18 ρcalcg/cm3 1.625 μ/mm-1 0.225 F(000) 1080.0 Crystal size/mm3 ? × ? × ? Radiation synchrotron (λ = 0.49555) 2Θ range for data collection/° 3.724 to 38.58 Index ranges -7 ≤ h ≤ 12, -16 ≤ k ≤ 16, -20 ≤ l ≤ 20 Reflections collected 4729 Independent reflections 1400 [Rint = 0.0373, Rsigma = 0.0434] Data/restraints/parameters 1400/0/88 Goodness-of-fit on F2 1.105 S19  Final R indexes [I>=2σ (I)] R1 = 0.0522, wR2 = 0.1235 Final R indexes [all data] R1 = 0.0785, wR2 = 0.1334 Largest diff. peak/hole / e Å-3 0.45/-0.28     Table 23 Fractional Atomic Coordinates (×104) and Equivalent Isotropic Displacement Parameters (Å2×103) for AlPO4-17 at 0.414 GPa. Ueq is defined as 1/3 of the trace of the orthogonalised UIJ tensor. Atom x y z U(eq) P1 9971.2(9) 2371.0(9) 1016.0(5) 19.6(3) P2 5744.9(12) 9079.2(12) 2500 17.6(3) Al2 922.0(14) 4234.9(14) 2500 16.8(4) Al1 7612.4(10) 9973.9(10) 1009.6(6) 18.8(3) O1 235(3) 3425(3) 1585.1(15) 32.0(7) O1B 6456(3) 9690(3) 1687.7(15) 34.1(7) O2 906(3) 2012(3) 1147.0(18) 39.0(8) O3 1329(3) 2549(3) 6271.3(15) 31.6(7) O4 2766(3) 40(3) 10066.5(14) 35.7(8) O5 2381(4) 4596(4) 2500 36.7(10) O6 4640(3) 9172(4) 2500 29.1(9)   Table S24 Anisotropic Displacement Parameters (Å2×103) for AlPO4-17 at 0.414 GPa. The Anisotropic displacement factor exponent takes the form: -2π2[h2a*2U11+2hka*b*U12+…]. Atom U11 U22 U33 U23 U13 U12 P1 17.4(6) 19.2(6) 19.9(4) -3.3(3) -0.3(3) 7.3(5) P2 13.0(7) 17.9(8) 22.3(5) 0 0 8.0(6) Al2 17.5(9) 14.0(9) 19.9(6) 0 0 8.6(7) Al1 18.6(6) 17.6(7) 17.9(5) 0.5(4) 2.6(4) 7.5(5) O1 40.5(19) 23.2(17) 27.7(12) -6.3(10) -1.6(11) 12.5(15) O1B 28.1(18) 43(2) 31.5(14) 7.0(12) 11.4(11) 17.7(16) O2 30.7(19) 39(2) 51.1(17) 5.7(13) 5.0(12) 20.0(16) O3 23.4(17) 38.2(19) 39.9(13) -9.3(11) -4.8(11) 20.5(15) O4 41(2) 47(2) 20.5(12) 2.3(11) 3.4(10) 22.7(17) O5 23(3) 25(3) 63(3) 0 0 13(2) O6 19(2) 38(3) 37.1(18) 0 0 20(2)   S20  Table S25 Bond Lengths for AlPO4-17 at 0.414 GPa. Atom Atom Length/Å   Atom Atom Length/Å P1 O11 1.512(3)   Al1 O25 1.718(3) P1 O21 1.521(3)   Al1 O36 1.705(3) P1 O32 1.516(3)   Al1 O47 1.711(2) P1 O43 1.522(2)   O1 P18 1.512(3) P2 O1B 1.513(3)   O2 P18 1.521(3) P2 O1B4 1.513(3)   O2 Al19 1.718(3) P2 O55 1.514(4)   O3 P110 1.516(3) P2 O6 1.503(4)   O3 Al111 1.705(3) Al2 O1 1.708(3)   O4 P112 1.522(2) Al2 O14 1.708(3)   O4 Al17 1.711(2) Al2 O5 1.715(4)   O5 P29 1.514(4) Al2 O65 1.672(4)   O6 Al29 1.672(4) Al1 O1B 1.708(3)         11+X,+Y,+Z; 21-Y+X,+X,-1/2+Z; 31-Y,+X-Y,-1+Z; 4+X,+Y,1/2-Z; 51-Y,1+X-Y,+Z; 61-Y+X,1+X,-1/2+Z; 71-X,1-Y,1-Z; 8-1+X,+Y,+Z; 9+Y-X,1-X,+Z; 10+Y,1-X+Y,1/2+Z; 11-1+Y,-X+Y,1/2+Z; 121+Y-X,1-X,1+Z   Table S26 Bond Angles for AlPO4-17 at 0.414 GPa. Atom Atom Atom Angle/˚   Atom Atom Atom Angle/˚ O11 P1 O21 110.57(17)   O65 Al2 O14 109.03(14) O11 P1 O32 109.39(16)   O65 Al2 O5 109.9(2) O11 P1 O43 107.58(18)   O1B Al1 O25 109.28(16) O21 P1 O43 110.46(17)   O1B Al1 O46 111.10(16) O32 P1 O21 108.04(17)   O37 Al1 O1B 108.45(15) O32 P1 O43 110.81(16)   O37 Al1 O25 110.33(16) O1B P2 O1B4 109.9(3)   O37 Al1 O46 109.81(14) O1B4 P2 O55 110.30(16)   O46 Al1 O25 107.87(15) O1B P2 O55 110.30(16)   P18 O1 Al2 147.2(2) O6 P2 O1B4 108.50(15)   P2 O1B Al1 148.4(2) O6 P2 O1B 108.50(15)   P18 O2 Al19 146.7(2) O6 P2 O55 109.3(2)   P110 O3 Al111 148.41(17) O1 Al2 O14 109.5(2)   P112 O4 Al16 145.6(2) O1 Al2 O5 109.66(14)   P29 O5 Al2 151.6(3) O14 Al2 O5 109.66(14)   P2 O6 Al29 172.4(3) O65 Al2 O1 109.03(14)           11+X,+Y,+Z; 21-Y+X,+X,-1/2+Z; 31-Y,+X-Y,-1+Z; 4+X,+Y,1/2-Z; 51-Y,1+X-Y,+Z; 61-X,1-Y,1-Z; 71-Y+X,1+X,-1/2+Z; 8-1+X,+Y,+Z; 9+Y-X,1-X,+Z; 10+Y,1-X+Y,1/2+Z; 11-1+Y,-X+Y,1/2+Z; 121+Y-X,1-X,1+Z    S21  Table S27 Crystal data and structure refinement for AlPO4-17 at 0.549 GPa. Identification code 17_SC05_P5 Empirical formula O4AlP Formula weight 121.95 Temperature/K 293(2) Crystal system hexagonal Space group P63/m a/Å 13.0191(11) b/Å 13.0191(11) c/Å 15.2329(6) α/° 90 β/° 90 γ/° 120 Volume/Å3 2236.0(4) Z 18 ρcalcg/cm3 1.630 μ/mm-1 0.226 F(000) 1080.0 Crystal size/mm3 ? × ? × ? Radiation synchrotron (λ = 0.49555) 2Θ range for data collection/° 3.728 to 38.572 Index ranges -8 ≤ h ≤ 13, -12 ≤ k ≤ 7, -20 ≤ l ≤ 20 Reflections collected 4785 Independent reflections 1402 [Rint = 0.0412, Rsigma = 0.0471] Data/restraints/parameters 1402/0/88 Goodness-of-fit on F2 1.109 Final R indexes [I>=2σ (I)] R1 = 0.0585, wR2 = 0.1360 Final R indexes [all data] R1 = 0.0944, wR2 = 0.1493 Largest diff. peak/hole / e Å-3 0.36/-0.27     Table S28 Fractional Atomic Coordinates (×104) and Equivalent Isotropic Displacement Parameters (Å2×103) for AlPO4-17 at 0.549 GPa. Ueq is defined as 1/3 of the trace of the orthogonalised UIJ tensor. Atom x y z U(eq) P1 9971.9(10) 2370.3(10) 1016.8(6) 26.8(3) P2 5743.4(14) 9076.7(14) 2500 24.4(4) Al2 925.4(16) 4236.1(16) 2500 23.7(4) Al1 7613.5(12) 9975.2(12) 1010.4(7) 26.0(4) O1 233(3) 3425(3) 1583.5(17) 41.1(9) O1B 6454(3) 9688(3) 1686.2(17) 43.4(9) O2 903(3) 2009(3) 1148(2) 46.1(9) O3 1328(3) 2551(3) 6274.8(17) 38.5(8) S22  Table S28 Fractional Atomic Coordinates (×104) and Equivalent Isotropic Displacement Parameters (Å2×103) for AlPO4-17 at 0.549 GPa. Ueq is defined as 1/3 of the trace of the orthogonalised UIJ tensor. Atom x y z U(eq) O4 2766(4) 40(3) 10065.4(16) 44.1(9) O5 2384(4) 4594(4) 2500 45.3(12) O6 4642(4) 9172(4) 2500 36.4(11)   Table S29 Anisotropic Displacement Parameters (Å2×103) for AlPO4-17 at 0.549 GPa. The Anisotropic displacement factor exponent takes the form: -2π2[h2a*2U11+2hka*b*U12+…]. Atom U11 U22 U33 U23 U13 U12 P1 25.4(7) 27.9(7) 24.5(5) -3.8(4) -0.6(4) 11.4(6) P2 20.3(9) 25.9(9) 27.6(6) 0 0 12.0(7) Al2 26.9(11) 20.9(10) 25.6(7) 0 0 13.6(9) Al1 26.6(8) 25.8(8) 23.7(6) 1.0(4) 2.9(5) 11.6(6) O1 49(2) 33(2) 35.1(15) -7.1(12) -0.5(13) 15.7(18) O1B 36(2) 52(2) 37.6(16) 6.0(14) 11.8(13) 18.6(19) O2 37(2) 49(2) 56.9(19) 6.5(15) 5.0(15) 25.7(19) O3 29.7(19) 47(2) 45.5(15) -11.1(13) -8.2(13) 24.3(18) O4 53(2) 58(2) 26.4(14) 1.4(13) 3.4(12) 31(2) O5 32(3) 33(3) 71(3) 0 0 16(2) O6 26(3) 44(3) 45(2) 0 0 22(2)   Table S30 Bond Lengths for AlPO4-17 at 0.549 GPa. Atom Atom Length/Å   Atom Atom Length/Å P1 O11 1.510(3)   Al1 O25 1.720(4) P1 O21 1.517(4)   Al1 O36 1.700(3) P1 O32 1.519(3)   Al1 O47 1.709(3) P1 O43 1.524(3)   O1 P18 1.510(3) P2 O1B4 1.513(3)   O2 P18 1.517(4) P2 O1B 1.513(3)   O2 Al19 1.720(4) P2 O55 1.505(5)   O3 P110 1.519(3) P2 O6 1.500(4)   O3 Al111 1.700(3) Al2 O1 1.710(3)   O4 P112 1.524(3) Al2 O14 1.710(3)   O4 Al17 1.709(3) Al2 O5 1.714(5)   O5 P29 1.505(5) Al2 O65 1.673(5)   O6 Al29 1.673(5) Al1 O1B 1.707(3)         11+X,+Y,+Z; 21-Y+X,+X,-1/2+Z; 31-Y,+X-Y,-1+Z; 4+X,+Y,1/2-Z; 51-Y,1+X-Y,+Z; 61-Y+X,1+X,-1/2+Z; 71-X,1-Y,1-Z; 8-1+X,+Y,+Z; 9+Y-X,1-X,+Z; 10+Y,1-X+Y,1/2+Z; 11-1+Y,-X+Y,1/2+Z; 121+Y-X,1-X,1+Z S23    Table S31 Bond Angles for AlPO4-17 at 0.549 GPa. Atom Atom Atom Angle/˚   Atom Atom Atom Angle/˚ O11 P1 O21 110.8(2)   O65 Al2 O14 108.87(16) O11 P1 O32 109.21(18)   O65 Al2 O5 110.1(2) O11 P1 O43 107.4(2)   O1B Al1 O25 109.33(18) O21 P1 O32 108.0(2)   O1B Al1 O46 110.92(19) O21 P1 O43 110.50(19)   O37 Al1 O1B 108.41(17) O32 P1 O43 110.85(18)   O37 Al1 O25 110.36(18) O1B P2 O1B4 110.0(3)   O37 Al1 O46 110.00(17) O55 P2 O1B 110.32(18)   O46 Al1 O25 107.83(17) O55 P2 O1B4 110.32(18)   P18 O1 Al2 146.9(2) O6 P2 O1B4 108.37(17)   P2 O1B Al1 148.3(3) O6 P2 O1B 108.37(17)   P18 O2 Al19 146.6(3) O6 P2 O55 109.4(3)   P110 O3 Al111 148.04(19) O1 Al2 O14 109.4(3)   P112 O4 Al16 145.5(3) O1 Al2 O5 109.77(16)   P29 O5 Al2 151.7(4) O14 Al2 O5 109.77(16)   P2 O6 Al29 172.2(3) O65 Al2 O1 108.87(16)           11+X,+Y,+Z; 21-Y+X,+X,-1/2+Z; 31-Y,+X-Y,-1+Z; 4+X,+Y,1/2-Z; 51-Y,1+X-Y,+Z; 61-X,1-Y,1-Z; 71-Y+X,1+X,-1/2+Z; 8-1+X,+Y,+Z; 9+Y-X,1-X,+Z; 10+Y,1-X+Y,1/2+Z; 11-1+Y,-X+Y,1/2+Z; 121+Y-X,1-X,1+Z    Table S32 Crystal data and structure refinement for AlPO4-17 at 0.723 GPa. Identification code 17_SC05_P6b Empirical formula O4AlP Formula weight 121.95 Temperature/K 293(2) Crystal system hexagonal Space group P63/m a/Å 12.9981(13) b/Å 12.9981(13) c/Å 15.2105(7) α/° 90 β/° 90 γ/° 120 Volume/Å3 2225.5(5) Z 18 ρcalcg/cm3 1.638 μ/mm-1 0.227 F(000) 1080.0 S24  Crystal size/mm3 ? × ? × ? Radiation synchrotron (λ = 0.49555) 2Θ range for data collection/° 3.734 to 38.532 Index ranges -8 ≤ h ≤ 13, -12 ≤ k ≤ 8, -20 ≤ l ≤ 20 Reflections collected 4741 Independent reflections 1375 [Rint = 0.0678, Rsigma = 0.0835] Data/restraints/parameters 1375/0/88 Goodness-of-fit on F2 1.130 Final R indexes [I>=2σ (I)] R1 = 0.1095, wR2 = 0.2539 Final R indexes [all data] R1 = 0.1691, wR2 = 0.2838 Largest diff. peak/hole / e Å-3 1.00/-0.52     Table S33 Fractional Atomic Coordinates (×104) and Equivalent Isotropic Displacement Parameters (Å2×103) for AlPO4-17 at 0.723 GPa. Ueq is defined as 1/3 of the trace of the orthogonalised UIJ tensor. Atom x y z U(eq) P1 9973(2) 2369(2) 1017.9(10) 41.5(7) P2 5737(3) 9072(3) 2500 38.6(9) Al2 930(3) 4241(3) 2500 39.0(10) Al1 7617(2) 9977(2) 1010.7(12) 39.2(8) O1 227(6) 3425(6) 1583(3) 62(2) O1B 6455(6) 9688(7) 1689(3) 61(2) O2 908(6) 2013(7) 1140(4) 65(2) O3 1334(6) 2554(6) 6274(3) 56.6(17) O4 2759(7) 34(6) 10059(3) 62(2) O5 2384(8) 4599(8) 2500 58(2) O6 4658(8) 9180(8) 2500 54(2)   Table S34 Anisotropic Displacement Parameters (Å2×103) for AlPO4-17 at 0.723 GPa. The Anisotropic displacement factor exponent takes the form: -2π2[h2a*2U11+2hka*b*U12+…]. Atom U11 U22 U33 U23 U13 U12 P1 47.7(15) 52.0(16) 24.2(9) -3.6(8) -0.7(8) 24.4(13) P2 42(2) 48(2) 25.2(11) 0 0 22.7(16) Al2 51(2) 44(2) 22.1(12) 0 0 23.5(19) Al1 46.4(16) 47.4(17) 22.1(10) 1.4(8) 2.7(9) 22.2(13) O1 83(5) 55(4) 32(2) -6(2) -3(3) 21(4) O1B 64(5) 82(5) 30(2) 8(3) 13(2) 33(4) O2 69(5) 78(5) 53(3) 10(3) 7(3) 40(4) O3 60(4) 71(5) 42(3) -9(3) -6(3) 35(4) S25  Table S34 Anisotropic Displacement Parameters (Å2×103) for AlPO4-17 at 0.723 GPa. The Anisotropic displacement factor exponent takes the form: -2π2[h2a*2U11+2hka*b*U12+…]. Atom U11 U22 U33 U23 U13 U12 O4 79(5) 72(5) 30(3) 2(2) 6(2) 34(4) O5 62(7) 42(6) 69(5) 0 0 24(5) O6 62(6) 61(6) 45(4) 0 0 35(5)   Table S35 Bond Lengths for AlPO4-17 at 0.723 GPa. Atom Atom Length/Å   Atom Atom Length/Å P1 O11 1.510(6)   Al1 O25 1.710(7) P1 O21 1.513(7)   Al1 O36 1.699(7) P1 O32 1.511(6)   Al1 O47 1.698(5) P1 O43 1.531(5)   O1 P18 1.510(6) P2 O1B4 1.512(5)   O2 P18 1.513(7) P2 O1B 1.513(5)   O2 Al19 1.710(7) P2 O55 1.503(9)   O3 P110 1.511(6) P2 O6 1.478(9)   O3 Al111 1.699(7) Al2 O1 1.713(6)   O4 P112 1.531(5) Al2 O14 1.713(6)   O4 Al17 1.698(5) Al2 O5 1.705(10)   O5 P29 1.503(9) Al2 O65 1.684(9)   O6 Al29 1.684(9) Al1 O1B 1.708(6)         11+X,+Y,+Z; 21-Y+X,+X,-1/2+Z; 31-Y,+X-Y,-1+Z; 4+X,+Y,1/2-Z; 51-Y,1+X-Y,+Z; 61-Y+X,1+X,-1/2+Z; 71-X,1-Y,1-Z; 8-1+X,+Y,+Z; 9+Y-X,1-X,+Z; 10+Y,1-X+Y,1/2+Z; 11-1+Y,-X+Y,1/2+Z; 121+Y-X,1-X,1+Z   Table S36 Bond Angles for AlPO4-17 at 0.723 GPa. Atom Atom Atom Angle/˚   Atom Atom Atom Angle/˚ O11 P1 O21 111.4(4)   O65 Al2 O1 108.5(3) O11 P1 O32 108.9(3)   O65 Al2 O5 110.6(4) O11 P1 O43 107.4(4)   O1B Al1 O25 109.3(3) O21 P1 O43 109.7(4)   O36 Al1 O1B 108.4(3) O32 P1 O21 108.6(4)   O36 Al1 O25 110.9(3) O32 P1 O43 110.9(3)   O47 Al1 O1B 111.0(4) O1B4 P2 O1B 109.4(6)   O47 Al1 O25 107.5(3) O55 P2 O1B 110.3(3)   O47 Al1 O36 109.8(3) O55 P2 O1B4 110.3(3)   P18 O1 Al2 146.4(5) O6 P2 O1B 108.3(3)   P2 O1B Al1 148.6(5) O6 P2 O1B4 108.3(3)   P18 O2 Al19 147.4(5) O6 P2 O55 110.1(5)   P110 O3 Al111 148.0(3) O14 Al2 O1 109.0(5)   P112 O4 Al17 145.7(6) O5 Al2 O1 110.2(3)   P29 O5 Al2 151.8(6) S26  Table S36 Bond Angles for AlPO4-17 at 0.723 GPa. Atom Atom Atom Angle/˚   Atom Atom Atom Angle/˚ O5 Al2 O14 110.2(3)   P2 O6 Al29 171.0(6) O65 Al2 O14 108.5(3)           11+X,+Y,+Z; 21-Y+X,+X,-1/2+Z; 31-Y,+X-Y,-1+Z; 4+X,+Y,1/2-Z; 51-Y,1+X-Y,+Z; 61-Y+X,1+X,-1/2+Z; 71-X,1-Y,1-Z; 8-1+X,+Y,+Z; 9+Y-X,1-X,+Z; 10+Y,1-X+Y,1/2+Z; 11-1+Y,-X+Y,1/2+Z; 121+Y-X,1-X,1+Z   Table S37 Crystal data and structure refinement for AlPO4-17 at 0.834 GPa. Identification code 17_SC05_P7 Empirical formula O4AlP Formula weight 121.95 Temperature/K 293(2) Crystal system hexagonal Space group P63/m a/Å 12.9715(14) b/Å 12.9715(14) c/Å 15.1870(7) α/° 90 β/° 90 γ/° 120 Volume/Å3 2213.0(5) Z 18 ρcalcg/cm3 1.647 μ/mm-1 0.228 F(000) 1080.0 Crystal size/mm3 ? × ? × ? Radiation synchrotron (λ = 0.49555) 2Θ range for data collection/° 3.74 to 38.572 Index ranges -8 ≤ h ≤ 12, -16 ≤ k ≤ 16, -20 ≤ l ≤ 20 Reflections collected 4591 Independent reflections 1366 [Rint = 0.0779, Rsigma = 0.1022] Data/restraints/parameters 1366/0/88 Goodness-of-fit on F2 1.046 Final R indexes [I>=2σ (I)] R1 = 0.1148, wR2 = 0.2657 Final R indexes [all data] R1 = 0.2009, wR2 = 0.3112 Largest diff. peak/hole / e Å-3 0.90/-0.54     S27  Table S38 Fractional Atomic Coordinates (×104) and Equivalent Isotropic Displacement Parameters (Å2×103) for AlPO4-17 at 0.834 GPa. Ueq is defined as 1/3 of the trace of the orthogonalised UIJ tensor. Atom x y z U(eq) P1 9970(3) 2369(2) 1019.3(12) 49.3(9) P2 5731(3) 9065(4) 2500 45.0(10) Al2 934(4) 4248(4) 2500 44.5(11) Al1 7614(3) 9973(3) 1012.4(13) 46.8(9) O1 229(8) 3429(7) 1586(3) 75(3) O1B 6457(7) 9689(8) 1691(3) 72(3) O2 898(7) 2004(8) 1140(4) 73(2) O3 1328(7) 2554(7) 6272(3) 64(2) O4 2768(8) 45(7) 10061(3) 70(2) O5 2383(9) 4604(9) 2500 68(3) O6 4652(10) 9170(9) 2500 67(3)   Table S39 Anisotropic Displacement Parameters (Å2×103) for AlPO4-17 at 0.834 GPa. The Anisotropic displacement factor exponent takes the form: -2π2[h2a*2U11+2hka*b*U12+…]. Atom U11 U22 U33 U23 U13 U12 P1 57.7(19) 60(2) 28.9(10) -3.9(10) -1.9(10) 28.3(16) P2 52(3) 57(3) 30.6(13) 0 0 30(2) Al2 57(3) 51(3) 27.4(15) 0 0 28(2) Al1 57(2) 56(2) 26.3(12) 1.3(10) 2.8(11) 28.1(17) O1 111(7) 74(6) 35(3) -13(3) -7(3) 42(5) O1B 70(6) 92(6) 39(3) 4(3) 15(3) 29(5) O2 72(6) 93(6) 58(4) 9(3) 6(3) 46(5) O3 62(5) 78(6) 48(3) -8(3) -5(3) 33(4) O4 92(6) 80(6) 32(3) 5(3) 3(3) 38(5) O5 70(8) 54(7) 74(6) 0 0 26(6) O6 85(8) 73(8) 50(5) 0 0 46(7)   Table S40 Bond Lengths for AlPO4-17 at 0.834 GPa. Atom Atom Length/Å   Atom Atom Length/Å P1 O11 1.511(7)   Al1 O25 1.714(8) P1 O21 1.508(8)   Al1 O36 1.693(8) P1 O32 1.510(7)   Al1 O47 1.701(6) P1 O43 1.529(6)   O1 P18 1.511(7) P2 O1B 1.513(6)   O2 P18 1.508(8) P2 O1B4 1.513(6)   O2 Al19 1.714(8) P2 O55 1.500(11)   O3 P110 1.510(7) P2 O6 1.473(11)   O3 Al111 1.693(8) S28  Table S40 Bond Lengths for AlPO4-17 at 0.834 GPa. Atom Atom Length/Å   Atom Atom Length/Å Al2 O14 1.709(7)   O4 P112 1.529(6) Al2 O1 1.709(7)   O4 Al17 1.701(6) Al2 O5 1.695(11)   O5 P29 1.500(11) Al2 O65 1.673(11)   O6 Al29 1.673(11) Al1 O1B 1.702(7)         11+X,+Y,+Z; 21-Y+X,+X,-1/2+Z; 31-Y,+X-Y,-1+Z; 4+X,+Y,1/2-Z; 51-Y,1+X-Y,+Z; 61-Y+X,1+X,-1/2+Z; 71-X,1-Y,1-Z; 8-1+X,+Y,+Z; 9+Y-X,1-X,+Z; 10+Y,1-X+Y,1/2+Z; 11-1+Y,-X+Y,1/2+Z; 121+Y-X,1-X,1+Z   Table S41 Bond Angles for AlPO4-17 at 0.834 GPa. Atom Atom Atom Angle/˚   Atom Atom Atom Angle/˚ O11 P1 O42 107.4(5)   O65 Al2 O14 108.7(4) O21 P1 O11 111.5(4)   O65 Al2 O5 110.3(5) O21 P1 O33 108.2(4)   O1B Al1 O25 109.8(4) O21 P1 O42 110.0(4)   O36 Al1 O1B 108.3(4) O33 P1 O11 109.3(4)   O36 Al1 O25 110.6(4) O33 P1 O42 110.4(4)   O36 Al1 O47 109.8(3) O1B4 P2 O1B 108.6(7)   O47 Al1 O1B 111.0(4) O55 P2 O1B4 110.6(4)   O47 Al1 O25 107.4(4) O55 P2 O1B 110.6(4)   P18 O1 Al2 146.6(6) O6 P2 O1B 108.5(4)   P2 O1B Al1 148.5(6) O6 P2 O1B4 108.5(4)   P18 O2 Al19 146.8(6) O6 P2 O55 110.0(6)   P110 O3 Al111 148.3(4) O14 Al2 O1 108.7(6)   P112 O4 Al17 145.6(7) O5 Al2 O1 110.2(4)   P29 O5 Al2 151.8(8) O5 Al2 O14 110.2(4)   P2 O6 Al29 171.4(8) O65 Al2 O1 108.7(4)           11+X,+Y,+Z; 21-Y,+X-Y,-1+Z; 31-Y+X,+X,-1/2+Z; 4+X,+Y,1/2-Z; 51-Y,1+X-Y,+Z; 61-Y+X,1+X,-1/2+Z; 71-X,1-Y,1-Z; 8-1+X,+Y,+Z; 9+Y-X,1-X,+Z; 10+Y,1-X+Y,1/2+Z; 11-1+Y,-X+Y,1/2+Z; 121+Y-X,1-X,1+Z   Table S42 Crystal data and structure refinement for AlPO4-17 at 0.97 GPa. Identification code 17_SC05_P8 Empirical formula O4AlP Formula weight 121.95 Temperature/K 293(2) Crystal system hexagonal Space group P63/m a/Å 12.885(3) b/Å 12.885(3) c/Å 15.1515(11) S29  α/° 90 β/° 90 γ/° 120 Volume/Å3 2178.7(10) Z 18 ρcalcg/cm3 1.673 μ/mm-1 0.232 F(000) 1080.0 Crystal size/mm3 ? × ? × ? Radiation synchrotron (λ = 0.49555) 2Θ range for data collection/° 3.748 to 28.58 Index ranges -7 ≤ h ≤ 9, -9 ≤ k ≤ 6, -15 ≤ l ≤ 15 Reflections collected 2027 Independent reflections 590 [Rint = 0.0633, Rsigma = 0.0849] Data/restraints/parameters 590/0/88 Goodness-of-fit on F2 1.167 Final R indexes [I>=2σ (I)] R1 = 0.0907, wR2 = 0.2016 Final R indexes [all data] R1 = 0.1438, wR2 = 0.2265 Largest diff. peak/hole / e Å-3 0.29/-0.34     Table S43 Fractional Atomic Coordinates (×104) and Equivalent Isotropic Displacement Parameters (Å2×103) for AlPO4-17 at 0.834 GPa. Ueq is defined as 1/3 of the trace of the orthogonalised UIJ tensor. Atom x y z U(eq) P1 9964(5) 2375(5) 1012(2) 83.3(19) P2 5728(6) 9053(6) 2500 71(2) Al2 931(7) 4253(7) 2500 71(2) Al1 7597(5) 9969(5) 1007(2) 79.4(19) O1 246(12) 3450(12) 1584(6) 108(5) O1B 6446(14) 9684(13) 1708(6) 123(6) O2 910(11) 1997(12) 1128(6) 110(4) O3 1325(10) 2558(10) 6264(5) 92(4) O4 2802(13) 51(11) 10065(5) 104(4) O5 2380(14) 4637(16) 2500 96(5) O6 4669(16) 9208(16) 2500 115(6)   S30  Table S44 Anisotropic Displacement Parameters (Å2×103) for AlPO4-17 at 0.834 GPa. The Anisotropic displacement factor exponent takes the form: -2π2[h2a*2U11+2hka*b*U12+…]. Atom U11 U22 U33 U23 U13 U12 P1 95(4) 112(5) 48(2) -10(3) -12(2) 55(4) P2 71(5) 88(6) 54(3) 0 0 40(4) Al2 82(6) 78(6) 54(3) 0 0 40(5) Al1 102(5) 90(4) 48(2) 9(2) 15(3) 49(4) O1 111(11) 108(12) 94(7) -37(7) -13(6) 46(9) O1B 148(14) 143(14) 77(6) 27(7) 51(7) 72(12) O2 93(10) 170(13) 79(7) 8(6) 0(5) 74(10) O3 92(10) 133(11) 62(5) -20(5) -3(5) 63(9) O4 117(12) 102(9) 70(6) 6(5) -6(6) 38(8) O5 84(13) 112(15) 100(10) 0 0 56(12) O6 80(14) 107(17) 169(15) 0 0 56(13)   Table S45 Bond Lengths for AlPO4-17 at 0.834 GPa. Atom Atom Length/Å   Atom Atom Length/Å P1 O11 1.517(13)   Al1 O25 1.695(12) P1 O21 1.531(13)   Al1 O36 1.686(12) P1 O32 1.506(11)   Al1 O47 1.699(9) P1 O43 1.519(10)   O1 P18 1.517(13) P2 O1B 1.485(10)   O2 P18 1.531(13) P2 O1B4 1.485(10)   O2 Al19 1.695(12) P2 O55 1.508(17)   O3 P110 1.506(11) P2 O6 1.475(18)   O3 Al111 1.686(12) Al2 O1 1.692(12)   O4 P112 1.519(10) Al2 O14 1.692(12)   O4 Al17 1.699(9) Al2 O5 1.676(18)   O5 P29 1.508(17) Al2 O65 1.653(19)   O6 Al29 1.653(19) Al1 O1B 1.708(13)         11+X,+Y,+Z; 21-Y+X,+X,-1/2+Z; 31-Y,+X-Y,-1+Z; 4+X,+Y,1/2-Z; 51-Y,1+X-Y,+Z; 61-Y+X,1+X,-1/2+Z; 71-X,1-Y,1-Z; 8-1+X,+Y,+Z; 9+Y-X,1-X,+Z; 10+Y,1-X+Y,1/2+Z; 11-1+Y,-X+Y,1/2+Z; 121+Y-X,1-X,1+Z   Table S46 Bond Angles for AlPO4-17 at 0.834 GPa. Atom Atom Atom Angle/˚   Atom Atom Atom Angle/˚ O11 P1 O21 111.1(7)   O65 Al2 O14 107.9(6) O11 P1 O42 106.4(8)   O65 Al2 O5 110.6(9) O33 P1 O11 110.2(7)   O25 Al1 O1B 110.1(7) O33 P1 O21 107.9(7)   O25 Al1 O46 107.7(6) O33 P1 O42 110.8(6)   O37 Al1 O1B 108.0(6) O42 P1 O21 110.4(7)   O37 Al1 O25 109.4(7) S31  Table S46 Bond Angles for AlPO4-17 at 0.834 GPa. Atom Atom Atom Angle/˚   Atom Atom Atom Angle/˚ O1B P2 O1B4 107.8(12)   O37 Al1 O46 110.1(6) O1B P2 O55 111.9(7)   O46 Al1 O1B 111.6(7) O1B4 P2 O55 111.9(7)   P18 O1 Al2 147.2(9) O6 P2 O1B 106.9(8)   P2 O1B Al1 149.0(11) O6 P2 O1B4 106.9(8)   P18 O2 Al19 145.9(9) O6 P2 O55 111.1(10)   P110 O3 Al111 148.8(6) O14 Al2 O1 110.2(11)   P112 O4 Al16 143.8(11) O5 Al2 O1 110.1(6)   P29 O5 Al2 149.6(13) O5 Al2 O14 110.1(6)   P2 O6 Al29 167.9(13) O65 Al2 O1 107.9(6)           11+X,+Y,+Z; 21-Y,+X-Y,-1+Z; 31-Y+X,+X,-1/2+Z; 4+X,+Y,1/2-Z; 51-Y,1+X-Y,+Z; 61-X,1-Y,1-Z; 71-Y+X,1+X,-1/2+Z; 8-1+X,+Y,+Z; 9+Y-X,1-X,+Z; 10+Y,1-X+Y,1/2+Z; 11-1+Y,-X+Y,1/2+Z; 121+Y-X,1-X,1+Z    Table S47 Crystal data and structure refinement for AlPO4-17 at 0.97 GPa. Identification code 17_SC05_P9 Empirical formula O4AlP Formula weight 121.95 Temperature/K 293(2) Crystal system hexagonal Space group P63/m a/Å 12.749(5) b/Å 12.749(5) c/Å 15.1232(16) α/° 90 β/° 90 γ/° 120 Volume/Å3 2128.7(18) Z 18 ρcalcg/cm3 1.712 μ/mm-1 0.238 F(000) 1080.0 Crystal size/mm3 ? × ? × ? Radiation synchrotron (λ = 0.49555) 2Θ range for data collection/° 3.756 to 24.884 Index ranges -6 ≤ h ≤ 8, -8 ≤ k ≤ 5, -13 ≤ l ≤ 13 Reflections collected 1386 Independent reflections 382 [Rint = 0.0560, Rsigma = 0.0567] Data/restraints/parameters 382/0/88 Goodness-of-fit on F2 1.176 S32  Final R indexes [I>=2σ (I)] R1 = 0.1371, wR2 = 0.2148 Final R indexes [all data] R1 = 0.1782, wR2 = 0.2317 Largest diff. peak/hole / e Å-3 0.33/-0.28     Table S48 Fractional Atomic Coordinates (×104) and Equivalent Isotropic Displacement Parameters (Å2×103) for AlPO4-17 at 0.97 GPa. Ueq is defined as 1/3 of the trace of the orthogonalised UIJ tensor. Atom x y z U(eq) P1 9961(18) 2470(20) 996(8) 174(7) P2 5691(19) 9042(18) 2500 145(7) Al2 910(20) 4263(19) 2500 145(7) Al1 7570(20) 9942(18) 983(8) 177(8) O1 200(40) 3450(40) 1645(18) 220(20) O1B 6450(30) 9580(30) 1739(13) 230(20) O2 910(30) 2070(30) 1117(13) 187(13) O3 1330(40) 2510(20) 6243(10) 174(13) O4 2950(30) 120(20) 10063(15) 165(12) O5 2320(30) 4690(40) 2500 165(16) O6 4680(50) 9200(50) 2500 260(30)   Table S49 Anisotropic Displacement Parameters (Å2×103) for AlPO4-17 at 0.97 GPa. The Anisotropic displacement factor exponent takes the form: -2π2[h2a*2U11+2hka*b*U12+…]. Atom U11 U22 U33 U23 U13 U12 P1 150(15) 220(20) 113(12) 10(10) -30(9) 59(14) P2 140(20) 150(19) 107(10) 0 0 45(17) Al2 140(20) 124(17) 124(12) 0 0 32(13) Al1 290(30) 141(14) 118(11) 41(9) 51(11) 119(17) O1 230(50) 280(60) 190(20) -110(30) -90(30) 150(50) O1B 190(40) 210(40) 119(16) 63(17) 85(19) -40(30) O2 160(30) 300(40) 140(20) 13(18) -3(17) 140(30) O3 220(40) 180(30) 58(13) -16(12) 4(18) 50(30) O4 200(30) 120(20) 122(13) 39(13) 15(18) 37(19) O5 60(30) 240(50) 160(30) 0 0 60(30) O6 80(50) 230(70) 460(90) 0 0 70(40)   S33  Table S50 Bond Lengths for AlPO4-17 at 0.97 GPa. Atom Atom Length/Å   Atom Atom Length/Å P1 O11 1.50(3)   Al1 O25 1.69(3) P1 O21 1.55(3)   Al1 O36 1.73(4) P1 O32 1.51(4)   Al1 O47 1.70(3) P1 O43 1.50(3)   O1 P18 1.50(3) P2 O1B 1.44(2)   O2 P18 1.55(3) P2 O1B4 1.44(2)   O2 Al19 1.69(3) P2 O55 1.61(4)   O3 P110 1.51(4) P2 O6 1.40(5)   O3 Al111 1.73(4) Al2 O14 1.62(3)   O4 P112 1.50(3) Al2 O1 1.62(3)   O4 Al17 1.70(3) Al2 O5 1.60(4)   O5 P29 1.61(4) Al2 O65 1.63(5)   O6 Al29 1.63(5) Al1 O1B 1.71(4)         11+X,+Y,+Z; 21-Y+X,+X,-1/2+Z; 31-Y,+X-Y,-1+Z; 4+X,+Y,1/2-Z; 51-Y,1+X-Y,+Z; 61-Y+X,1+X,-1/2+Z; 71-X,1-Y,1-Z; 8-1+X,+Y,+Z; 9+Y-X,1-X,+Z; 10+Y,1-X+Y,1/2+Z; 11-1+Y,-X+Y,1/2+Z; 121+Y-X,1-X,1+Z   Table S51 Bond Angles for AlPO4-17 at 0.97 GPa. Atom Atom Atom Angle/˚   Atom Atom Atom Angle/˚ O11 P1 O21 109.6(19)   O5 Al2 O1 113(2) O11 P1 O32 110(2)   O5 Al2 O65 107(3) O11 P1 O43 112(3)   O1B Al1 O36 109.9(16) O32 P1 O21 101(2)   O25 Al1 O1B 103(2) O43 P1 O21 113.2(18)   O25 Al1 O36 110(2) O43 P1 O32 110.3(15)   O25 Al1 O47 109.6(15) O1B P2 O1B4 106(3)   O47 Al1 O1B 111(2) O1B4 P2 O55 107(2)   O47 Al1 O36 113.2(12) O1B P2 O55 107(2)   P18 O1 Al2 150(3) O6 P2 O1B4 112(3)   P2 O1B Al1 160(4) O6 P2 O1B 112(3)   P18 O2 Al19 147(3) O6 P2 O55 112(3)   P110 O3 Al111 151.9(14) O14 Al2 O1 106(4)   P112 O4 Al17 138(2) O14 Al2 O65 108(2)   Al2 O5 P29 148(4) O1 Al2 O65 108(2)   P2 O6 Al29 168(5) O5 Al2 O14 113(2)           11+X,+Y,+Z; 21-Y+X,+X,-1/2+Z; 31-Y,+X-Y,-1+Z; 4+X,+Y,1/2-Z; 51-Y,1+X-Y,+Z; 61-Y+X,1+X,-1/2+Z; 71-X,1-Y,1-Z; 8-1+X,+Y,+Z; 9+Y-X,1-X,+Z; 10+Y,1-X+Y,1/2+Z; 11-1+Y,-X+Y,1/2+Z; 121+Y-X,1-X,1+Z   17_SC05_P10 S34  Table S52 Crystal data and structure refinement for AlPO4-17 at 1.11 GPa. Identification code 17_SC05_P10 Empirical formula AlO4P Formula weight 121.95 Temperature/K 293(2) Crystal system hexagonal Space group P63/m a/Å 12.64(3) b/Å 12.64(3) c/Å 15.121(8) α/° 90 β/° 90 γ/° 120 Volume/Å3 2093(10) Z 18 ρcalcg/cm3 1.741 μ/mm-1 0.242 F(000) 1080.0 Crystal size/mm3 ? × ? × ? Radiation synchrotron (λ = 0.49555) 2Θ range for data collection/° 3.756 to 20.378 Index ranges -5 ≤ h ≤ 6, -6 ≤ k ≤ 4, -10 ≤ l ≤ 10 Reflections collected 719 Independent reflections 194 [Rint = 0.0736, Rsigma = 0.0645] Data/restraints/parameters 194/0/41 Goodness-of-fit on F2 1.226 Final R indexes [I>=2σ (I)] R1 = 0.1772, wR2 = 0.4214 Final R indexes [all data] R1 = 0.2155, wR2 = 0.4495 Largest diff. peak/hole / e Å-3 0.30/-0.39     Table S53 Fractional Atomic Coordinates (×104) and Equivalent Isotropic Displacement Parameters (Å2×103) for AlPO4-17 at 1.11 GPa. Ueq is defined as 1/3 of the trace of the orthogonalised UIJ tensor. Atom x y z U(eq) P1 9950(20) 2350(20) 1041(14) 142(10) P2 5740(40) 9090(50) 2500 171(15) Al2 1050(50) 4440(50) 2500 176(16) Al1 7500(30) 9970(30) 971(15) 159(11) O1 100(90) 3490(90) 1590(40) 250(30) O1B 6340(90) 9810(90) 1720(40) 250(30) O2 1030(50) 1910(60) 1030(30) 176(18) O3 1300(40) 2530(30) 6228(19) 104(14) S35  Table S53 Fractional Atomic Coordinates (×104) and Equivalent Isotropic Displacement Parameters (Å2×103) for AlPO4-17 at 1.11 GPa. Ueq is defined as 1/3 of the trace of the orthogonalised UIJ tensor. Atom x y z U(eq) O4 2840(60) 150(50) 10160(30) 190(30) O5 2420(70) 4530(60) 2500 140(20) O6 4750(190) 9300(130) 2500 330(60)   Table S54 Bond Lengths for AlPO4-17 at 1.11 GPa. Atom Atom Length/Å   Atom Atom Length/Å P1 O11 1.60(9)   Al1 O25 1.58(5) P1 O21 1.71(5)   Al1 O36 1.68(5) P1 O32 1.45(4)   Al1 O47 1.76(5) P1 O43 1.42(5)   O1 P18 1.60(9) P2 O1B 1.45(7)   O2 P18 1.71(5) P2 O1B4 1.45(7)   O2 Al19 1.58(5) P2 O55 1.38(7)   O3 P110 1.45(4) P2 O6 1.40(18)   O3 Al111 1.68(5) Al2 O1 1.82(9)   O4 P112 1.42(5) Al2 O14 1.82(9)   O4 Al17 1.76(5) Al2 O5 1.68(7)   O5 P29 1.38(7) Al2 O65 1.55(18)   O6 Al29 1.55(18) Al1 O1B 1.78(9)         11+X,+Y,+Z; 21-Y+X,+X,-1/2+Z; 31-Y,+X-Y,-1+Z; 4+X,+Y,1/2-Z; 51-Y,1+X-Y,+Z; 61-Y+X,1+X,-1/2+Z; 71-X,1-Y,1-Z; 8-1+X,+Y,+Z; 9+Y-X,1-X,+Z; 10+Y,1-X+Y,1/2+Z; 11-1+Y,-X+Y,1/2+Z; 121+Y-X,1-X,1+Z   Table S55 Bond Angles for AlPO4-17 at 1.11 GPa. Atom Atom Atom Angle/˚   Atom Atom Atom Angle/˚ O11 P1 O21 123(4)   O65 Al2 O14 100(5) O32 P1 O11 109(4)   O65 Al2 O5 131(7) O32 P1 O21 109(3)   O25 Al1 O1B 122(4) O43 P1 O11 102(4)   O25 Al1 O36 98(3) O43 P1 O21 107(3)   O25 Al1 O47 101(3) O43 P1 O32 105(3)   O36 Al1 O1B 106(3) O1B4 P2 O1B 109(8)   O36 Al1 O47 112(2) O55 P2 O1B4 117(5)   O47 Al1 O1B 117(4) O55 P2 O1B 117(5)   P18 O1 Al2 136(6) O55 P2 O6 117(8)   P2 O1B Al1 137(7) O6 P2 O1B4 97(6)   Al19 O2 P18 140(5) O6 P2 O1B 97(6)   P110 O3 Al111 154(2) O14 Al2 O1 98(7)   P112 O4 Al17 146(5) O5 Al2 O1 112(4)   P29 O5 Al2 164(6) S36  Table S55 Bond Angles for AlPO4-17 at 1.11 GPa. 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